Merge commit 'origin/master' into next

Manual merge of:
	drivers/char/hvc_console.c
	drivers/char/hvc_console.h

3 files changed, 1441 insertions, 147 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index e023682be2c4..3141dd3b6e53 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -666,6 +666,14 @@ config VIRTIO_CONSOLE
         help
           Virtio console for use with lguest and other hypervisors.
 
+          Also serves as a general-purpose serial device for data
+          transfer between the guest and host.  Character devices at
+          /dev/vportNpn will be created when corresponding ports are
+          found, where N is the device number and n is the port number
+          within that device.  If specified by the host, a sysfs
+          attribute called 'name' will be populated with a name for
+          the port which can be used by udev scripts to create a
+          symlink to the device.
 
 config HVCS
         tristate "IBM Hypervisor Virtual Console Server support"
diff --git a/drivers/char/hvc_beat.c b/drivers/char/hvc_beat.c
index 6913fc33270c..5fe4631e2a61 100644
--- a/drivers/char/hvc_beat.c
+++ b/drivers/char/hvc_beat.c
@@ -99,7 +99,7 @@ static int hvc_beat_config(char *p)
 
 static int __init hvc_beat_console_init(void)
 {
-        if (hvc_beat_useit && machine_is_compatible("Beat")) {
+        if (hvc_beat_useit && of_machine_is_compatible("Beat")) {
                 hvc_instantiate(0, 0, &hvc_beat_get_put_ops);
         }
         return 0;
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index a035ae39a359..213373b5f17f 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1,18 +1,6 @@
-/*D:300
- * The Guest console driver
- *
- * Writing console drivers is one of the few remaining Dark Arts in Linux.
- * Fortunately for us, the path of virtual consoles has been well-trodden by
- * the PowerPC folks, who wrote "hvc_console.c" to generically support any
- * virtual console.  We use that infrastructure which only requires us to write
- * the basic put_chars and get_chars functions and call the right register
- * functions.
- :*/
-
-/*M:002 The console can be flooded: while the Guest is processing input the
- * Host can send more.  Buffering in the Host could alleviate this, but it is a
- * difficult problem in general. :*/
-/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+/*
+ * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
+ * Copyright (C) 2009, 2010 Red Hat, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -28,142 +16,694 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+#include <linux/cdev.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
 #include <linux/err.h>
+#include <linux/fs.h>
 #include <linux/init.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
 #include <linux/virtio.h>
 #include <linux/virtio_console.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
 #include "hvc_console.h"
 
-/*D:340 These represent our input and output console queues, and the virtio
- * operations for them. */
-static struct virtqueue *in_vq, *out_vq;
-static struct virtio_device *vdev;
+/*
+ * This is a global struct for storing common data for all the devices
+ * this driver handles.
+ *
+ * Mainly, it has a linked list for all the consoles in one place so
+ * that callbacks from hvc for get_chars(), put_chars() work properly
+ * across multiple devices and multiple ports per device.
+ */
+struct ports_driver_data {
+        /* Used for registering chardevs */
+        struct class *class;
+
+        /* Used for exporting per-port information to debugfs */
+        struct dentry *debugfs_dir;
+
+        /* Number of devices this driver is handling */
+        unsigned int index;
+
+        /*
+         * This is used to keep track of the number of hvc consoles
+         * spawned by this driver.  This number is given as the first
+         * argument to hvc_alloc().  To correctly map an initial
+         * console spawned via hvc_instantiate to the console being
+         * hooked up via hvc_alloc, we need to pass the same vtermno.
+         *
+         * We also just assume the first console being initialised was
+         * the first one that got used as the initial console.
+         */
+        unsigned int next_vtermno;
+
+        /* All the console devices handled by this driver */
+        struct list_head consoles;
+};
+static struct ports_driver_data pdrvdata;
+
+DEFINE_SPINLOCK(pdrvdata_lock);
+
+/* This struct holds information that's relevant only for console ports */
+struct console {
+        /* We'll place all consoles in a list in the pdrvdata struct */
+        struct list_head list;
+
+        /* The hvc device associated with this console port */
+        struct hvc_struct *hvc;
+
+        /*
+         * This number identifies the number that we used to register
+         * with hvc in hvc_instantiate() and hvc_alloc(); this is the
+         * number passed on by the hvc callbacks to us to
+         * differentiate between the other console ports handled by
+         * this driver
+         */
+        u32 vtermno;
+};
+
+struct port_buffer {
+        char *buf;
+
+        /* size of the buffer in *buf above */
+        size_t size;
+
+        /* used length of the buffer */
+        size_t len;
+        /* offset in the buf from which to consume data */
+        size_t offset;
+};
+
+/*
+ * This is a per-device struct that stores data common to all the
+ * ports for that device (vdev->priv).
+ */
+struct ports_device {
+        /*
+         * Workqueue handlers where we process deferred work after
+         * notification
+         */
+        struct work_struct control_work;
+        struct work_struct config_work;
+
+        struct list_head ports;
+
+        /* To protect the list of ports */
+        spinlock_t ports_lock;
+
+        /* To protect the vq operations for the control channel */
+        spinlock_t cvq_lock;
+
+        /* The current config space is stored here */
+        struct virtio_console_config config;
+
+        /* The virtio device we're associated with */
+        struct virtio_device *vdev;
+
+        /*
+         * A couple of virtqueues for the control channel: one for
+         * guest->host transfers, one for host->guest transfers
+         */
+        struct virtqueue *c_ivq, *c_ovq;
+
+        /* Array of per-port IO virtqueues */
+        struct virtqueue **in_vqs, **out_vqs;
+
+        /* Used for numbering devices for sysfs and debugfs */
+        unsigned int drv_index;
+
+        /* Major number for this device.  Ports will be created as minors. */
+        int chr_major;
+};
+
+/* This struct holds the per-port data */
+struct port {
+        /* Next port in the list, head is in the ports_device */
+        struct list_head list;
+
+        /* Pointer to the parent virtio_console device */
+        struct ports_device *portdev;
+
+        /* The current buffer from which data has to be fed to readers */
+        struct port_buffer *inbuf;
+
+        /*
+         * To protect the operations on the in_vq associated with this
+         * port.  Has to be a spinlock because it can be called from
+         * interrupt context (get_char()).
+         */
+        spinlock_t inbuf_lock;
+
+        /* The IO vqs for this port */
+        struct virtqueue *in_vq, *out_vq;
+
+        /* File in the debugfs directory that exposes this port's information */
+        struct dentry *debugfs_file;
+
+        /*
+         * The entries in this struct will be valid if this port is
+         * hooked up to an hvc console
+         */
+        struct console cons;
+
+        /* Each port associates with a separate char device */
+        struct cdev cdev;
+        struct device *dev;
+
+        /* A waitqueue for poll() or blocking read operations */
+        wait_queue_head_t waitqueue;
+
+        /* The 'name' of the port that we expose via sysfs properties */
+        char *name;
+
+        /* The 'id' to identify the port with the Host */
+        u32 id;
+
+        /* Is the host device open */
+        bool host_connected;
+
+        /* We should allow only one process to open a port */
+        bool guest_connected;
+};
+
+/* This is the very early arch-specified put chars function. */
+static int (*early_put_chars)(u32, const char *, int);
+
+static struct port *find_port_by_vtermno(u32 vtermno)
+{
+        struct port *port;
+        struct console *cons;
+        unsigned long flags;
+
+        spin_lock_irqsave(&pdrvdata_lock, flags);
+        list_for_each_entry(cons, &pdrvdata.consoles, list) {
+                if (cons->vtermno == vtermno) {
+                        port = container_of(cons, struct port, cons);
+                        goto out;
+                }
+        }
+        port = NULL;
+out:
+        spin_unlock_irqrestore(&pdrvdata_lock, flags);
+        return port;
+}
+
+static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
+{
+        struct port *port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&portdev->ports_lock, flags);
+        list_for_each_entry(port, &portdev->ports, list)
+                if (port->id == id)
+                        goto out;
+        port = NULL;
+out:
+        spin_unlock_irqrestore(&portdev->ports_lock, flags);
+
+        return port;
+}
+
+static struct port *find_port_by_vq(struct ports_device *portdev,
+                                    struct virtqueue *vq)
+{
+        struct port *port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&portdev->ports_lock, flags);
+        list_for_each_entry(port, &portdev->ports, list)
+                if (port->in_vq == vq || port->out_vq == vq)
+                        goto out;
+        port = NULL;
+out:
+        spin_unlock_irqrestore(&portdev->ports_lock, flags);
+        return port;
+}
+
+static bool is_console_port(struct port *port)
+{
+        if (port->cons.hvc)
+                return true;
+        return false;
+}
+
+static inline bool use_multiport(struct ports_device *portdev)
+{
+        /*
+         * This condition can be true when put_chars is called from
+         * early_init
+         */
+        if (!portdev->vdev)
+                return 0;
+        return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
+}
 
-/* This is our input buffer, and how much data is left in it. */
-static unsigned int in_len;
-static char *in, *inbuf;
+static void free_buf(struct port_buffer *buf)
+{
+        kfree(buf->buf);
+        kfree(buf);
+}
+
+static struct port_buffer *alloc_buf(size_t buf_size)
+{
+        struct port_buffer *buf;
 
-/* The operations for our console. */
-static struct hv_ops virtio_cons;
+        buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+        if (!buf)
+                goto fail;
+        buf->buf = kzalloc(buf_size, GFP_KERNEL);
+        if (!buf->buf)
+                goto free_buf;
+        buf->len = 0;
+        buf->offset = 0;
+        buf->size = buf_size;
+        return buf;
+
+free_buf:
+        kfree(buf);
+fail:
+        return NULL;
+}
+
+/* Callers should take appropriate locks */
+static void *get_inbuf(struct port *port)
+{
+        struct port_buffer *buf;
+        struct virtqueue *vq;
+        unsigned int len;
 
-/* The hvc device */
-static struct hvc_struct *hvc;
+        vq = port->in_vq;
+        buf = vq->vq_ops->get_buf(vq, &len);
+        if (buf) {
+                buf->len = len;
+                buf->offset = 0;
+        }
+        return buf;
+}
 
-/*D:310 The put_chars() callback is pretty straightforward.
+/*
+ * Create a scatter-gather list representing our input buffer and put
+ * it in the queue.
  *
- * We turn the characters into a scatter-gather list, add it to the output
- * queue and then kick the Host.  Then we sit here waiting for it to finish:
- * inefficient in theory, but in practice implementations will do it
- * immediately (lguest's Launcher does). */
-static int put_chars(u32 vtermno, const char *buf, int count)
+ * Callers should take appropriate locks.
+ */
+static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
 {
         struct scatterlist sg[1];
+        int ret;
+
+        sg_init_one(sg, buf->buf, buf->size);
+
+        ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
+        vq->vq_ops->kick(vq);
+        return ret;
+}
+
+/* Discard any unread data this port has. Callers lockers. */
+static void discard_port_data(struct port *port)
+{
+        struct port_buffer *buf;
+        struct virtqueue *vq;
         unsigned int len;
+        int ret;
 
-        /* This is a convenient routine to initialize a single-elem sg list */
-        sg_init_one(sg, buf, count);
+        vq = port->in_vq;
+        if (port->inbuf)
+                buf = port->inbuf;
+        else
+                buf = vq->vq_ops->get_buf(vq, &len);
 
-        /* add_buf wants a token to identify this buffer: we hand it any
-         * non-NULL pointer, since there's only ever one buffer. */
-        if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) {
-                /* Tell Host to go! */
-                out_vq->vq_ops->kick(out_vq);
-                /* Chill out until it's done with the buffer. */
-                while (!out_vq->vq_ops->get_buf(out_vq, &len))
-                        cpu_relax();
+        ret = 0;
+        while (buf) {
+                if (add_inbuf(vq, buf) < 0) {
+                        ret++;
+                        free_buf(buf);
+                }
+                buf = vq->vq_ops->get_buf(vq, &len);
         }
+        port->inbuf = NULL;
+        if (ret)
+                dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
+                         ret);
+}
 
-        /* We're expected to return the amount of data we wrote: all of it. */
-        return count;
+static bool port_has_data(struct port *port)
+{
+        unsigned long flags;
+        bool ret;
+
+        spin_lock_irqsave(&port->inbuf_lock, flags);
+        if (port->inbuf) {
+                ret = true;
+                goto out;
+        }
+        port->inbuf = get_inbuf(port);
+        if (port->inbuf) {
+                ret = true;
+                goto out;
+        }
+        ret = false;
+out:
+        spin_unlock_irqrestore(&port->inbuf_lock, flags);
+        return ret;
 }
 
-/* Create a scatter-gather list representing our input buffer and put it in the
- * queue. */
-static void add_inbuf(void)
+static ssize_t send_control_msg(struct port *port, unsigned int event,
+                                unsigned int value)
 {
         struct scatterlist sg[1];
-        sg_init_one(sg, inbuf, PAGE_SIZE);
+        struct virtio_console_control cpkt;
+        struct virtqueue *vq;
+        int len;
+
+        if (!use_multiport(port->portdev))
+                return 0;
+
+        cpkt.id = port->id;
+        cpkt.event = event;
+        cpkt.value = value;
+
+        vq = port->portdev->c_ovq;
 
-        /* We should always be able to add one buffer to an empty queue. */
-        if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0)
-                BUG();
-        in_vq->vq_ops->kick(in_vq);
+        sg_init_one(sg, &cpkt, sizeof(cpkt));
+        if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
+                vq->vq_ops->kick(vq);
+                while (!vq->vq_ops->get_buf(vq, &len))
+                        cpu_relax();
+        }
+        return 0;
 }
 
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
- *
- * Most of the code deals with the fact that the hvc_console() infrastructure
- * only asks us for 16 bytes at a time.  We keep in_offset and in_used fields
- * for partially-filled buffers. */
-static int get_chars(u32 vtermno, char *buf, int count)
+static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
 {
-        /* If we don't have an input queue yet, we can't get input. */
-        BUG_ON(!in_vq);
+        struct scatterlist sg[1];
+        struct virtqueue *out_vq;
+        ssize_t ret;
+        unsigned int len;
+
+        out_vq = port->out_vq;
+
+        sg_init_one(sg, in_buf, in_count);
+        ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
+
+        /* Tell Host to go! */
+        out_vq->vq_ops->kick(out_vq);
+
+        if (ret < 0) {
+                len = 0;
+                goto fail;
+        }
+
+        /*
+         * Wait till the host acknowledges it pushed out the data we
+         * sent. Also ensure we return to userspace the number of
+         * bytes that were successfully consumed by the host.
+         */
+        while (!out_vq->vq_ops->get_buf(out_vq, &len))
+                cpu_relax();
+fail:
+        /* We're expected to return the amount of data we wrote */
+        return len;
+}
+
+/*
+ * Give out the data that's requested from the buffer that we have
+ * queued up.
+ */
+static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
+                            bool to_user)
+{
+        struct port_buffer *buf;
+        unsigned long flags;
+
+        if (!out_count || !port_has_data(port))
+                return 0;
+
+        buf = port->inbuf;
+        out_count = min(out_count, buf->len - buf->offset);
+
+        if (to_user) {
+                ssize_t ret;
+
+                ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
+                if (ret)
+                        return -EFAULT;
+        } else {
+                memcpy(out_buf, buf->buf + buf->offset, out_count);
+        }
+
+        buf->offset += out_count;
+
+        if (buf->offset == buf->len) {
+                /*
+                 * We're done using all the data in this buffer.
+                 * Re-queue so that the Host can send us more data.
+                 */
+                spin_lock_irqsave(&port->inbuf_lock, flags);
+                port->inbuf = NULL;
+
+                if (add_inbuf(port->in_vq, buf) < 0)
+                        dev_warn(port->dev, "failed add_buf\n");
+
+                spin_unlock_irqrestore(&port->inbuf_lock, flags);
+        }
+        /* Return the number of bytes actually copied */
+        return out_count;
+}
 
-        /* No buffer?  Try to get one. */
-        if (!in_len) {
-                in = in_vq->vq_ops->get_buf(in_vq, &in_len);
-                if (!in)
+/* The condition that must be true for polling to end */
+static bool wait_is_over(struct port *port)
+{
+        return port_has_data(port) || !port->host_connected;
+}
+
+static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
+                              size_t count, loff_t *offp)
+{
+        struct port *port;
+        ssize_t ret;
+
+        port = filp->private_data;
+
+        if (!port_has_data(port)) {
+                /*
+                 * If nothing's connected on the host just return 0 in
+                 * case of list_empty; this tells the userspace app
+                 * that there's no connection
+                 */
+                if (!port->host_connected)
                         return 0;
+                if (filp->f_flags & O_NONBLOCK)
+                        return -EAGAIN;
+
+                ret = wait_event_interruptible(port->waitqueue,
+                                               wait_is_over(port));
+                if (ret < 0)
+                        return ret;
+        }
+        /*
+         * We could've received a disconnection message while we were
+         * waiting for more data.
+         *
+         * This check is not clubbed in the if() statement above as we
+         * might receive some data as well as the host could get
+         * disconnected after we got woken up from our wait.  So we
+         * really want to give off whatever data we have and only then
+         * check for host_connected.
+         */
+        if (!port_has_data(port) && !port->host_connected)
+                return 0;
+
+        return fill_readbuf(port, ubuf, count, true);
+}
+
+static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
+                               size_t count, loff_t *offp)
+{
+        struct port *port;
+        char *buf;
+        ssize_t ret;
+
+        port = filp->private_data;
+
+        count = min((size_t)(32 * 1024), count);
+
+        buf = kmalloc(count, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        ret = copy_from_user(buf, ubuf, count);
+        if (ret) {
+                ret = -EFAULT;
+                goto free_buf;
         }
 
-        /* You want more than we have to give?  Well, try wanting less! */
-        if (in_len < count)
-                count = in_len;
+        ret = send_buf(port, buf, count);
+free_buf:
+        kfree(buf);
+        return ret;
+}
+
+static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
+{
+        struct port *port;
+        unsigned int ret;
+
+        port = filp->private_data;
+        poll_wait(filp, &port->waitqueue, wait);
+
+        ret = 0;
+        if (port->inbuf)
+                ret |= POLLIN | POLLRDNORM;
+        if (port->host_connected)
+                ret |= POLLOUT;
+        if (!port->host_connected)
+                ret |= POLLHUP;
+
+        return ret;
+}
+
+static int port_fops_release(struct inode *inode, struct file *filp)
+{
+        struct port *port;
+
+        port = filp->private_data;
+
+        /* Notify host of port being closed */
+        send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
+
+        spin_lock_irq(&port->inbuf_lock);
+        port->guest_connected = false;
+
+        discard_port_data(port);
+
+        spin_unlock_irq(&port->inbuf_lock);
+
+        return 0;
+}
+
+static int port_fops_open(struct inode *inode, struct file *filp)
+{
+        struct cdev *cdev = inode->i_cdev;
+        struct port *port;
+
+        port = container_of(cdev, struct port, cdev);
+        filp->private_data = port;
+
+        /*
+         * Don't allow opening of console port devices -- that's done
+         * via /dev/hvc
+         */
+        if (is_console_port(port))
+                return -ENXIO;
+
+        /* Allow only one process to open a particular port at a time */
+        spin_lock_irq(&port->inbuf_lock);
+        if (port->guest_connected) {
+                spin_unlock_irq(&port->inbuf_lock);
+                return -EMFILE;
+        }
 
-        /* Copy across to their buffer and increment offset. */
-        memcpy(buf, in, count);
-        in += count;
-        in_len -= count;
+        port->guest_connected = true;
+        spin_unlock_irq(&port->inbuf_lock);
 
-        /* Finished?  Re-register buffer so Host will use it again. */
-        if (in_len == 0)
-                add_inbuf();
+        /* Notify host of port being opened */
+        send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
 
-        return count;
+        return 0;
 }
-/*:*/
 
-/*D:320 Console drivers are initialized very early so boot messages can go out,
- * so we do things slightly differently from the generic virtio initialization
- * of the net and block drivers.
+/*
+ * The file operations that we support: programs in the guest can open
+ * a console device, read from it, write to it, poll for data and
+ * close it.  The devices are at
+ *   /dev/vport<device number>p<port number>
+ */
+static const struct file_operations port_fops = {
+        .owner = THIS_MODULE,
+        .open  = port_fops_open,
+        .read  = port_fops_read,
+        .write = port_fops_write,
+        .poll  = port_fops_poll,
+        .release = port_fops_release,
+};
+
+/*
+ * The put_chars() callback is pretty straightforward.
  *
- * At this stage, the console is output-only.  It's too early to set up a
- * virtqueue, so we let the drivers do some boutique early-output thing. */
-int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
+ * We turn the characters into a scatter-gather list, add it to the
+ * output queue and then kick the Host.  Then we sit here waiting for
+ * it to finish: inefficient in theory, but in practice
+ * implementations will do it immediately (lguest's Launcher does).
+ */
+static int put_chars(u32 vtermno, const char *buf, int count)
 {
-        virtio_cons.put_chars = put_chars;
-        return hvc_instantiate(0, 0, &virtio_cons);
+        struct port *port;
+
+        port = find_port_by_vtermno(vtermno);
+        if (!port)
+                return 0;
+
+        if (unlikely(early_put_chars))
+                return early_put_chars(vtermno, buf, count);
+
+        return send_buf(port, (void *)buf, count);
 }
 
 /*
- * virtio console configuration. This supports:
- * - console resize
+ * get_chars() is the callback from the hvc_console infrastructure
+ * when an interrupt is received.
+ *
+ * We call out to fill_readbuf that gets us the required data from the
+ * buffers that are queued up.
  */
-static void virtcons_apply_config(struct virtio_device *dev)
+static int get_chars(u32 vtermno, char *buf, int count)
 {
+        struct port *port;
+
+        port = find_port_by_vtermno(vtermno);
+        if (!port)
+                return 0;
+
+        /* If we don't have an input queue yet, we can't get input. */
+        BUG_ON(!port->in_vq);
+
+        return fill_readbuf(port, buf, count, false);
+}
+
+static void resize_console(struct port *port)
+{
+        struct virtio_device *vdev;
         struct winsize ws;
 
-        if (virtio_has_feature(dev, VIRTIO_CONSOLE_F_SIZE)) {
-                dev->config->get(dev,
-                                 offsetof(struct virtio_console_config, cols),
-                                 &ws.ws_col, sizeof(u16));
-                dev->config->get(dev,
-                                 offsetof(struct virtio_console_config, rows),
-                                 &ws.ws_row, sizeof(u16));
-                hvc_resize(hvc, ws);
+        vdev = port->portdev->vdev;
+        if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
+                vdev->config->get(vdev,
+                                  offsetof(struct virtio_console_config, cols),
+                                  &ws.ws_col, sizeof(u16));
+                vdev->config->get(vdev,
+                                  offsetof(struct virtio_console_config, rows),
+                                  &ws.ws_row, sizeof(u16));
+                hvc_resize(port->cons.hvc, ws);
         }
 }
 
-/*
- * we support only one console, the hvc struct is a global var
- * We set the configuration at this point, since we now have a tty
- */
+/* We set the configuration at this point, since we now have a tty */
 static int notifier_add_vio(struct hvc_struct *hp, int data)
 {
+        struct port *port;
+
+        port = find_port_by_vtermno(hp->vtermno);
+        if (!port)
+                return -EINVAL;
+
         hp->irq_requested = 1;
-        virtcons_apply_config(vdev);
+        resize_console(port);
 
         return 0;
 }
@@ -173,79 +713,797 @@ static void notifier_del_vio(struct hvc_struct *hp, int data)
         hp->irq_requested = 0;
 }
 
-static void hvc_handle_input(struct virtqueue *vq)
+/* The operations for console ports. */
+static const struct hv_ops hv_ops = {
+        .get_chars = get_chars,
+        .put_chars = put_chars,
+        .notifier_add = notifier_add_vio,
+        .notifier_del = notifier_del_vio,
+        .notifier_hangup = notifier_del_vio,
+};
+
+/*
+ * Console drivers are initialized very early so boot messages can go
+ * out, so we do things slightly differently from the generic virtio
+ * initialization of the net and block drivers.
+ *
+ * At this stage, the console is output-only.  It's too early to set
+ * up a virtqueue, so we let the drivers do some boutique early-output
+ * thing.
+ */
+int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
 {
-        if (hvc_poll(hvc))
+        early_put_chars = put_chars;
+        return hvc_instantiate(0, 0, &hv_ops);
+}
+
+int init_port_console(struct port *port)
+{
+        int ret;
+
+        /*
+         * The Host's telling us this port is a console port.  Hook it
+         * up with an hvc console.
+         *
+         * To set up and manage our virtual console, we call
+         * hvc_alloc().
+         *
+         * The first argument of hvc_alloc() is the virtual console
+         * number.  The second argument is the parameter for the
+         * notification mechanism (like irq number).  We currently
+         * leave this as zero, virtqueues have implicit notifications.
+         *
+         * The third argument is a "struct hv_ops" containing the
+         * put_chars() get_chars(), notifier_add() and notifier_del()
+         * pointers.  The final argument is the output buffer size: we
+         * can do any size, so we put PAGE_SIZE here.
+         */
+        port->cons.vtermno = pdrvdata.next_vtermno;
+
+        port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
+        if (IS_ERR(port->cons.hvc)) {
+                ret = PTR_ERR(port->cons.hvc);
+                dev_err(port->dev,
+                        "error %d allocating hvc for port\n", ret);
+                port->cons.hvc = NULL;
+                return ret;
+        }
+        spin_lock_irq(&pdrvdata_lock);
+        pdrvdata.next_vtermno++;
+        list_add_tail(&port->cons.list, &pdrvdata.consoles);
+        spin_unlock_irq(&pdrvdata_lock);
+        port->guest_connected = true;
+
+        /* Notify host of port being opened */
+        send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
+
+        return 0;
+}
+
+static ssize_t show_port_name(struct device *dev,
+                              struct device_attribute *attr, char *buffer)
+{
+        struct port *port;
+
+        port = dev_get_drvdata(dev);
+
+        return sprintf(buffer, "%s\n", port->name);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
+
+static struct attribute *port_sysfs_entries[] = {
+        &dev_attr_name.attr,
+        NULL
+};
+
+static struct attribute_group port_attribute_group = {
+        .name = NULL,           /* put in device directory */
+        .attrs = port_sysfs_entries,
+};
+
+static int debugfs_open(struct inode *inode, struct file *filp)
+{
+        filp->private_data = inode->i_private;
+        return 0;
+}
+
+static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
+                            size_t count, loff_t *offp)
+{
+        struct port *port;
+        char *buf;
+        ssize_t ret, out_offset, out_count;
+
+        out_count = 1024;
+        buf = kmalloc(out_count, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        port = filp->private_data;
+        out_offset = 0;
+        out_offset += snprintf(buf + out_offset, out_count,
+                               "name: %s\n", port->name ? port->name : "");
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "guest_connected: %d\n", port->guest_connected);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "host_connected: %d\n", port->host_connected);
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "is_console: %s\n",
+                               is_console_port(port) ? "yes" : "no");
+        out_offset += snprintf(buf + out_offset, out_count - out_offset,
+                               "console_vtermno: %u\n", port->cons.vtermno);
+
+        ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
+        kfree(buf);
+        return ret;
+}
+
+static const struct file_operations port_debugfs_ops = {
+        .owner = THIS_MODULE,
+        .open  = debugfs_open,
+        .read  = debugfs_read,
+};
+
+/* Remove all port-specific data. */
+static int remove_port(struct port *port)
+{
+        struct port_buffer *buf;
+
+        spin_lock_irq(&port->portdev->ports_lock);
+        list_del(&port->list);
+        spin_unlock_irq(&port->portdev->ports_lock);
+
+        if (is_console_port(port)) {
+                spin_lock_irq(&pdrvdata_lock);
+                list_del(&port->cons.list);
+                spin_unlock_irq(&pdrvdata_lock);
+                hvc_remove(port->cons.hvc);
+        }
+        if (port->guest_connected)
+                send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
+
+        sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
+        device_destroy(pdrvdata.class, port->dev->devt);
+        cdev_del(&port->cdev);
+
+        /* Remove unused data this port might have received. */
+        discard_port_data(port);
+
+        /* Remove buffers we queued up for the Host to send us data in. */
+        while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
+                free_buf(buf);
+
+        kfree(port->name);
+
+        debugfs_remove(port->debugfs_file);
+
+        kfree(port);
+        return 0;
+}
+
+/* Any private messages that the Host and Guest want to share */
+static void handle_control_message(struct ports_device *portdev,
+                                   struct port_buffer *buf)
+{
+        struct virtio_console_control *cpkt;
+        struct port *port;
+        size_t name_size;
+        int err;
+
+        cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
+
+        port = find_port_by_id(portdev, cpkt->id);
+        if (!port) {
+                /* No valid header at start of buffer.  Drop it. */
+                dev_dbg(&portdev->vdev->dev,
+                        "Invalid index %u in control packet\n", cpkt->id);
+                return;
+        }
+
+        switch (cpkt->event) {
+        case VIRTIO_CONSOLE_CONSOLE_PORT:
+                if (!cpkt->value)
+                        break;
+                if (is_console_port(port))
+                        break;
+
+                init_port_console(port);
+                /*
+                 * Could remove the port here in case init fails - but
+                 * have to notify the host first.
+                 */
+                break;
+        case VIRTIO_CONSOLE_RESIZE:
+                if (!is_console_port(port))
+                        break;
+                port->cons.hvc->irq_requested = 1;
+                resize_console(port);
+                break;
+        case VIRTIO_CONSOLE_PORT_OPEN:
+                port->host_connected = cpkt->value;
+                wake_up_interruptible(&port->waitqueue);
+                break;
+        case VIRTIO_CONSOLE_PORT_NAME:
+                /*
+                 * Skip the size of the header and the cpkt to get the size
+                 * of the name that was sent
+                 */
+                name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
+
+                port->name = kmalloc(name_size, GFP_KERNEL);
+                if (!port->name) {
+                        dev_err(port->dev,
+                                "Not enough space to store port name\n");
+                        break;
+                }
+                strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
+                        name_size - 1);
+                port->name[name_size - 1] = 0;
+
+                /*
+                 * Since we only have one sysfs attribute, 'name',
+                 * create it only if we have a name for the port.
+                 */
+                err = sysfs_create_group(&port->dev->kobj,
+                                         &port_attribute_group);
+                if (err)
+                        dev_err(port->dev,
+                                "Error %d creating sysfs device attributes\n",
+                                err);
+
+                break;
+        case VIRTIO_CONSOLE_PORT_REMOVE:
+                /*
+                 * Hot unplug the port.  We don't decrement nr_ports
+                 * since we don't want to deal with extra complexities
+                 * of using the lowest-available port id: We can just
+                 * pick up the nr_ports number as the id and not have
+                 * userspace send it to us.  This helps us in two
+                 * ways:
+                 *
+                 * - We don't need to have a 'port_id' field in the
+                 *   config space when a port is hot-added.  This is a
+                 *   good thing as we might queue up multiple hotplug
+                 *   requests issued in our workqueue.
+                 *
+                 * - Another way to deal with this would have been to
+                 *   use a bitmap of the active ports and select the
+                 *   lowest non-active port from that map.  That
+                 *   bloats the already tight config space and we
+                 *   would end up artificially limiting the
+                 *   max. number of ports to sizeof(bitmap).  Right
+                 *   now we can support 2^32 ports (as the port id is
+                 *   stored in a u32 type).
+                 *
+                 */
+                remove_port(port);
+                break;
+        }
+}
+
+static void control_work_handler(struct work_struct *work)
+{
+        struct ports_device *portdev;
+        struct virtqueue *vq;
+        struct port_buffer *buf;
+        unsigned int len;
+
+        portdev = container_of(work, struct ports_device, control_work);
+        vq = portdev->c_ivq;
+
+        spin_lock(&portdev->cvq_lock);
+        while ((buf = vq->vq_ops->get_buf(vq, &len))) {
+                spin_unlock(&portdev->cvq_lock);
+
+                buf->len = len;
+                buf->offset = 0;
+
+                handle_control_message(portdev, buf);
+
+                spin_lock(&portdev->cvq_lock);
+                if (add_inbuf(portdev->c_ivq, buf) < 0) {
+                        dev_warn(&portdev->vdev->dev,
+                                 "Error adding buffer to queue\n");
+                        free_buf(buf);
+                }
+        }
+        spin_unlock(&portdev->cvq_lock);
+}
+
+static void in_intr(struct virtqueue *vq)
+{
+        struct port *port;
+        unsigned long flags;
+
+        port = find_port_by_vq(vq->vdev->priv, vq);
+        if (!port)
+                return;
+
+        spin_lock_irqsave(&port->inbuf_lock, flags);
+        if (!port->inbuf)
+                port->inbuf = get_inbuf(port);
+
+        /*
+         * Don't queue up data when port is closed.  This condition
+         * can be reached when a console port is not yet connected (no
+         * tty is spawned) and the host sends out data to console
+         * ports.  For generic serial ports, the host won't
+         * (shouldn't) send data till the guest is connected.
+         */
+        if (!port->guest_connected)
+                discard_port_data(port);
+
+        spin_unlock_irqrestore(&port->inbuf_lock, flags);
+
+        wake_up_interruptible(&port->waitqueue);
+
+        if (is_console_port(port) && hvc_poll(port->cons.hvc))
                 hvc_kick();
 }
 
-/*D:370 Once we're further in boot, we get probed like any other virtio device.
- * At this stage we set up the output virtqueue.
- *
- * To set up and manage our virtual console, we call hvc_alloc().  Since we
- * never remove the console device we never need this pointer again.
+static void control_intr(struct virtqueue *vq)
+{
+        struct ports_device *portdev;
+
+        portdev = vq->vdev->priv;
+        schedule_work(&portdev->control_work);
+}
+
+static void config_intr(struct virtio_device *vdev)
+{
+        struct ports_device *portdev;
+
+        portdev = vdev->priv;
+        if (use_multiport(portdev)) {
+                /* Handle port hot-add */
+                schedule_work(&portdev->config_work);
+        }
+        /*
+         * We'll use this way of resizing only for legacy support.
+         * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
+         * control messages to indicate console size changes so that
+         * it can be done per-port
+         */
+        resize_console(find_port_by_id(portdev, 0));
+}
+
+static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
+{
+        struct port_buffer *buf;
+        unsigned int ret;
+        int err;
+
+        ret = 0;
+        do {
+                buf = alloc_buf(PAGE_SIZE);
+                if (!buf)
+                        break;
+
+                spin_lock_irq(lock);
+                err = add_inbuf(vq, buf);
+                if (err < 0) {
+                        spin_unlock_irq(lock);
+                        free_buf(buf);
+                        break;
+                }
+                ret++;
+                spin_unlock_irq(lock);
+        } while (err > 0);
+
+        return ret;
+}
+
+static int add_port(struct ports_device *portdev, u32 id)
+{
+        char debugfs_name[16];
+        struct port *port;
+        struct port_buffer *buf;
+        dev_t devt;
+        int err;
+
+        port = kmalloc(sizeof(*port), GFP_KERNEL);
+        if (!port) {
+                err = -ENOMEM;
+                goto fail;
+        }
+
+        port->portdev = portdev;
+        port->id = id;
+
+        port->name = NULL;
+        port->inbuf = NULL;
+        port->cons.hvc = NULL;
+
+        port->host_connected = port->guest_connected = false;
+
+        port->in_vq = portdev->in_vqs[port->id];
+        port->out_vq = portdev->out_vqs[port->id];
+
+        cdev_init(&port->cdev, &port_fops);
+
+        devt = MKDEV(portdev->chr_major, id);
+        err = cdev_add(&port->cdev, devt, 1);
+        if (err < 0) {
+                dev_err(&port->portdev->vdev->dev,
+                        "Error %d adding cdev for port %u\n", err, id);
+                goto free_port;
+        }
+        port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
+                                  devt, port, "vport%up%u",
+                                  port->portdev->drv_index, id);
+        if (IS_ERR(port->dev)) {
+                err = PTR_ERR(port->dev);
+                dev_err(&port->portdev->vdev->dev,
+                        "Error %d creating device for port %u\n",
+                        err, id);
+                goto free_cdev;
+        }
+
+        spin_lock_init(&port->inbuf_lock);
+        init_waitqueue_head(&port->waitqueue);
+
+        /* Fill the in_vq with buffers so the host can send us data. */
+        err = fill_queue(port->in_vq, &port->inbuf_lock);
+        if (!err) {
+                dev_err(port->dev, "Error allocating inbufs\n");
+                err = -ENOMEM;
+                goto free_device;
+        }
+
+        /*
+         * If we're not using multiport support, this has to be a console port
+         */
+        if (!use_multiport(port->portdev)) {
+                err = init_port_console(port);
+                if (err)
+                        goto free_inbufs;
+        }
+
+        spin_lock_irq(&portdev->ports_lock);
+        list_add_tail(&port->list, &port->portdev->ports);
+        spin_unlock_irq(&portdev->ports_lock);
+
+        /*
+         * Tell the Host we're set so that it can send us various
+         * configuration parameters for this port (eg, port name,
+         * caching, whether this is a console port, etc.)
+         */
+        send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
+
+        if (pdrvdata.debugfs_dir) {
+                /*
+                 * Finally, create the debugfs file that we can use to
+                 * inspect a port's state at any time
+                 */
+                sprintf(debugfs_name, "vport%up%u",
+                        port->portdev->drv_index, id);
+                port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
+                                                         pdrvdata.debugfs_dir,
+                                                         port,
+                                                         &port_debugfs_ops);
+        }
+        return 0;
+
+free_inbufs:
+        while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
+                free_buf(buf);
+free_device:
+        device_destroy(pdrvdata.class, port->dev->devt);
+free_cdev:
+        cdev_del(&port->cdev);
+free_port:
+        kfree(port);
+fail:
+        return err;
+}
+
+/*
+ * The workhandler for config-space updates.
  *
- * Finally we put our input buffer in the input queue, ready to receive. */
-static int __devinit virtcons_probe(struct virtio_device *dev)
+ * This is called when ports are hot-added.
+ */
+static void config_work_handler(struct work_struct *work)
+{
+        struct virtio_console_config virtconconf;
+        struct ports_device *portdev;
+        struct virtio_device *vdev;
+        int err;
+
+        portdev = container_of(work, struct ports_device, config_work);
+
+        vdev = portdev->vdev;
+        vdev->config->get(vdev,
+                          offsetof(struct virtio_console_config, nr_ports),
+                          &virtconconf.nr_ports,
+                          sizeof(virtconconf.nr_ports));
+
+        if (portdev->config.nr_ports == virtconconf.nr_ports) {
+                /*
+                 * Port 0 got hot-added.  Since we already did all the
+                 * other initialisation for it, just tell the Host
+                 * that the port is ready if we find the port.  In
+                 * case the port was hot-removed earlier, we call
+                 * add_port to add the port.
+                 */
+                struct port *port;
+
+                port = find_port_by_id(portdev, 0);
+                if (!port)
+                        add_port(portdev, 0);
+                else
+                        send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
+                return;
+        }
+        if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
+                dev_warn(&vdev->dev,
+                         "More ports specified (%u) than allowed (%u)",
+                         portdev->config.nr_ports + 1,
+                         portdev->config.max_nr_ports);
+                return;
+        }
+        if (virtconconf.nr_ports < portdev->config.nr_ports)
+                return;
+
+        /* Hot-add ports */
+        while (virtconconf.nr_ports - portdev->config.nr_ports) {
+                err = add_port(portdev, portdev->config.nr_ports);
+                if (err)
+                        break;
+                portdev->config.nr_ports++;
+        }
+}
+
+static int init_vqs(struct ports_device *portdev)
 {
-        vq_callback_t *callbacks[] = { hvc_handle_input, NULL};
-        const char *names[] = { "input", "output" };
-        struct virtqueue *vqs[2];
+        vq_callback_t **io_callbacks;
+        char **io_names;
+        struct virtqueue **vqs;
+        u32 i, j, nr_ports, nr_queues;
         int err;
 
-        vdev = dev;
+        nr_ports = portdev->config.max_nr_ports;
+        nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
 
-        /* This is the scratch page we use to receive console input */
-        inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-        if (!inbuf) {
+        vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
+        if (!vqs) {
                 err = -ENOMEM;
                 goto fail;
         }
+        io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
+        if (!io_callbacks) {
+                err = -ENOMEM;
+                goto free_vqs;
+        }
+        io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
+        if (!io_names) {
+                err = -ENOMEM;
+                goto free_callbacks;
+        }
+        portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
+                                  GFP_KERNEL);
+        if (!portdev->in_vqs) {
+                err = -ENOMEM;
+                goto free_names;
+        }
+        portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
+                                   GFP_KERNEL);
+        if (!portdev->out_vqs) {
+                err = -ENOMEM;
+                goto free_invqs;
+        }
+
+        /*
+         * For backward compat (newer host but older guest), the host
+         * spawns a console port first and also inits the vqs for port
+         * 0 before others.
+         */
+        j = 0;
+        io_callbacks[j] = in_intr;
+        io_callbacks[j + 1] = NULL;
+        io_names[j] = "input";
+        io_names[j + 1] = "output";
+        j += 2;
 
+        if (use_multiport(portdev)) {
+                io_callbacks[j] = control_intr;
+                io_callbacks[j + 1] = NULL;
+                io_names[j] = "control-i";
+                io_names[j + 1] = "control-o";
+
+                for (i = 1; i < nr_ports; i++) {
+                        j += 2;
+                        io_callbacks[j] = in_intr;
+                        io_callbacks[j + 1] = NULL;
+                        io_names[j] = "input";
+                        io_names[j + 1] = "output";
+                }
+        }
         /* Find the queues. */
-        /* FIXME: This is why we want to wean off hvc: we do nothing
-         * when input comes in. */
-        err = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names);
+        err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
+                                              io_callbacks,
+                                              (const char **)io_names);
         if (err)
+                goto free_outvqs;
+
+        j = 0;
+        portdev->in_vqs[0] = vqs[0];
+        portdev->out_vqs[0] = vqs[1];
+        j += 2;
+        if (use_multiport(portdev)) {
+                portdev->c_ivq = vqs[j];
+                portdev->c_ovq = vqs[j + 1];
+
+                for (i = 1; i < nr_ports; i++) {
+                        j += 2;
+                        portdev->in_vqs[i] = vqs[j];
+                        portdev->out_vqs[i] = vqs[j + 1];
+                }
+        }
+        kfree(io_callbacks);
+        kfree(io_names);
+        kfree(vqs);
+
+        return 0;
+
+free_names:
+        kfree(io_names);
+free_callbacks:
+        kfree(io_callbacks);
+free_outvqs:
+        kfree(portdev->out_vqs);
+free_invqs:
+        kfree(portdev->in_vqs);
+free_vqs:
+        kfree(vqs);
+fail:
+        return err;
+}
+
+static const struct file_operations portdev_fops = {
+        .owner = THIS_MODULE,
+};
+
+/*
+ * Once we're further in boot, we get probed like any other virtio
+ * device.
+ *
+ * If the host also supports multiple console ports, we check the
+ * config space to see how many ports the host has spawned.  We
+ * initialize each port found.
+ */
+static int __devinit virtcons_probe(struct virtio_device *vdev)
+{
+        struct ports_device *portdev;
+        u32 i;
+        int err;
+        bool multiport;
+
+        portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
+        if (!portdev) {
+                err = -ENOMEM;
+                goto fail;
+        }
+
+        /* Attach this portdev to this virtio_device, and vice-versa. */
+        portdev->vdev = vdev;
+        vdev->priv = portdev;
+
+        spin_lock_irq(&pdrvdata_lock);
+        portdev->drv_index = pdrvdata.index++;
+        spin_unlock_irq(&pdrvdata_lock);
+
+        portdev->chr_major = register_chrdev(0, "virtio-portsdev",
+                                             &portdev_fops);
+        if (portdev->chr_major < 0) {
+                dev_err(&vdev->dev,
+                        "Error %d registering chrdev for device %u\n",
+                        portdev->chr_major, portdev->drv_index);
+                err = portdev->chr_major;
                 goto free;
+        }
 
-        in_vq = vqs[0];
-        out_vq = vqs[1];
+        multiport = false;
+        portdev->config.nr_ports = 1;
+        portdev->config.max_nr_ports = 1;
+        if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
+                multiport = true;
+                vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
 
-        /* Start using the new console output. */
-        virtio_cons.get_chars = get_chars;
-        virtio_cons.put_chars = put_chars;
-        virtio_cons.notifier_add = notifier_add_vio;
-        virtio_cons.notifier_del = notifier_del_vio;
-        virtio_cons.notifier_hangup = notifier_del_vio;
-
-        /* The first argument of hvc_alloc() is the virtual console number, so
-         * we use zero.  The second argument is the parameter for the
-         * notification mechanism (like irq number). We currently leave this
-         * as zero, virtqueues have implicit notifications.
-         *
-         * The third argument is a "struct hv_ops" containing the put_chars()
-         * get_chars(), notifier_add() and notifier_del() pointers.
-         * The final argument is the output buffer size: we can do any size,
-         * so we put PAGE_SIZE here. */
-        hvc = hvc_alloc(0, 0, &virtio_cons, PAGE_SIZE);
-        if (IS_ERR(hvc)) {
-                err = PTR_ERR(hvc);
-                goto free_vqs;
+                vdev->config->get(vdev, offsetof(struct virtio_console_config,
+                                                 nr_ports),
+                                  &portdev->config.nr_ports,
+                                  sizeof(portdev->config.nr_ports));
+                vdev->config->get(vdev, offsetof(struct virtio_console_config,
+                                                 max_nr_ports),
+                                  &portdev->config.max_nr_ports,
+                                  sizeof(portdev->config.max_nr_ports));
+                if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
+                        dev_warn(&vdev->dev,
+                                 "More ports (%u) specified than allowed (%u). Will init %u ports.",
+                                 portdev->config.nr_ports,
+                                 portdev->config.max_nr_ports,
+                                 portdev->config.max_nr_ports);
+
+                        portdev->config.nr_ports = portdev->config.max_nr_ports;
+                }
+        }
+
+        /* Let the Host know we support multiple ports.*/
+        vdev->config->finalize_features(vdev);
+
+        err = init_vqs(portdev);
+        if (err < 0) {
+                dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
+                goto free_chrdev;
+        }
+
+        spin_lock_init(&portdev->ports_lock);
+        INIT_LIST_HEAD(&portdev->ports);
+
+        if (multiport) {
+                spin_lock_init(&portdev->cvq_lock);
+                INIT_WORK(&portdev->control_work, &control_work_handler);
+                INIT_WORK(&portdev->config_work, &config_work_handler);
+
+                err = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+                if (!err) {
+                        dev_err(&vdev->dev,
+                                "Error allocating buffers for control queue\n");
+                        err = -ENOMEM;
+                        goto free_vqs;
+                }
         }
 
-        /* Register the input buffer the first time. */
-        add_inbuf();
+        for (i = 0; i < portdev->config.nr_ports; i++)
+                add_port(portdev, i);
+
+        /* Start using the new console output. */
+        early_put_chars = NULL;
         return 0;
 
 free_vqs:
         vdev->config->del_vqs(vdev);
+        kfree(portdev->in_vqs);
+        kfree(portdev->out_vqs);
+free_chrdev:
+        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
 free:
-        kfree(inbuf);
+        kfree(portdev);
 fail:
         return err;
 }
 
+static void virtcons_remove(struct virtio_device *vdev)
+{
+        struct ports_device *portdev;
+        struct port *port, *port2;
+        struct port_buffer *buf;
+        unsigned int len;
+
+        portdev = vdev->priv;
+
+        cancel_work_sync(&portdev->control_work);
+        cancel_work_sync(&portdev->config_work);
+
+        list_for_each_entry_safe(port, port2, &portdev->ports, list)
+                remove_port(port);
+
+        unregister_chrdev(portdev->chr_major, "virtio-portsdev");
+
+        while ((buf = portdev->c_ivq->vq_ops->get_buf(portdev->c_ivq, &len)))
+                free_buf(buf);
+
+        while ((buf = portdev->c_ivq->vq_ops->detach_unused_buf(portdev->c_ivq)))
+                free_buf(buf);
+
+        vdev->config->del_vqs(vdev);
+        kfree(portdev->in_vqs);
+        kfree(portdev->out_vqs);
+
+        kfree(portdev);
+}
+
 static struct virtio_device_id id_table[] = {
         { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
         { 0 },
@@ -253,6 +1511,7 @@ static struct virtio_device_id id_table[] = {
 
 static unsigned int features[] = {
         VIRTIO_CONSOLE_F_SIZE,
+        VIRTIO_CONSOLE_F_MULTIPORT,
 };
 
 static struct virtio_driver virtio_console = {
@@ -262,14 +1521,41 @@ static struct virtio_driver virtio_console = {
         .driver.owner = THIS_MODULE,
         .id_table =     id_table,
         .probe =        virtcons_probe,
-        .config_changed = virtcons_apply_config,
+        .remove =       virtcons_remove,
+        .config_changed = config_intr,
 };
 
 static int __init init(void)
 {
+        int err;
+
+        pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
+        if (IS_ERR(pdrvdata.class)) {
+                err = PTR_ERR(pdrvdata.class);
+                pr_err("Error %d creating virtio-ports class\n", err);
+                return err;
+        }
+
+        pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
+        if (!pdrvdata.debugfs_dir) {
+                pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
+                           PTR_ERR(pdrvdata.debugfs_dir));
+        }
+        INIT_LIST_HEAD(&pdrvdata.consoles);
+
         return register_virtio_driver(&virtio_console);
 }
+
+static void __exit fini(void)
+{
+        unregister_virtio_driver(&virtio_console);
+
+        class_destroy(pdrvdata.class);
+        if (pdrvdata.debugfs_dir)
+                debugfs_remove_recursive(pdrvdata.debugfs_dir);
+}
 module_init(init);
+module_exit(fini);
 
 MODULE_DEVICE_TABLE(virtio, id_table);
 MODULE_DESCRIPTION("Virtio console driver");